Making Stuff: Smarter looks at materials that respond to their environments and even learn, such as an airplane wing that changes shape as it flies. Scientists are turning to nature in developing such "smart" stuff. Sharkskin, for instance, has inspired a substance that, when sprayed in hospitals, could eliminate antibiotic-resistant bacteria. David Pogue visits a scientist who has even created a material that can render objects invisible. "Smarter" concludes with a vision of the ultimate in "life-like" stuff: programmable matter that could create a duplicate of a human being.